In an special report obtained by SPACE.com, two of Russia's leading UFO investigators have summarized the results of the Soviet Union's official 13-year study of UFO reports.

They maintain that the Western media claims of "secret KGB files" and "captured aliens" are untrue.

"One can hardly imagine a greater absurdity," they write, although they do admit that their own research program (1978-1990) was indeed classified "SECRET" at the time and that there remained cases that could not be explained.

The investigators, Dr. Yuliy Platov of the Academy of Sciences and Colonel Boris Sokolov of the Ministry of Defense, wrote up their conclusions for an issue of the official Reports of the Academy of Sciences journal, published in Moscow. Dr. Platov forwarded an advance copy of the report to SPACE.com.

"Many people are the eyewitnesses of strange things," the writers report, "which cannot always be precisely identified with natural or man-made effects. However, this amount is very insignificant, and from this there does not follow even a 'hint' of the probable interference of extraterrestrial forces into our lives."

In a brief background for the project, Platov and Sokolov describe how the mass UFO sighting of September 20, 1977, over the northwestern city of Petrozavodsk and elsewhere, sparked high-level public and official interest in UFOs. Two parallel studies, one within the civilian scientific establishment and one within the military, were set up to run for the following 13 years. The civilian team actually continued formal investigations until 1996, Platov reveals.

The official groups did not use the term "UFO" (or "NLO" in Russian). Instead, they referred to "paranormal phenomena." But everyone involved in the project knew exactly what this meant -- any apparently unexplainable aerial apparitions.

Platov and Sokolov explain that from the start, the teams "assumed a high probability of a military-technical origin of the observed strange effects."

This was based in large part on the iron-clad identification of the "Petrozavodsk UFO" with the launching of a spy satellite from a secret nearby base. But this factor dictated that the study be kept secret because most of the suspected causes were already military secrets.

Another reason for secrecy was "to decrease a public resonance" regarding the reality of UFOs -- a "resonance" that would only grow if the government's formal interest were known.

Finally, there was the possibility of military application of discoveries regarding some of the perceived properties of UFOs such as radar invisibility and high maneuverability.

Sokolov himself is widely quoted on Internet UFO pages endorsing this last possible benefit of UFO research. However, his more prosaic explanations for some "classic" Russian UFO cases failed to show up on several search engines I tried.

In January 1980, the Soviet Ministry of Defense issued a directive to all military forces to report "any inexplicable, exotic, extraordinary phenomenon". Sokolov described how this essentially converted millions of military personnel across one sixth of the Earth's surface into a sensory network for UFOs. "It is not likely that anybody could organize such a large-scale research," he boasted, "and practically with no financing."

Over the course of more than a decade, Platov's and Sokolov's teams together collected and analyzed about 3,000 detailed messages, covering about 400 individual events.

A pattern soon emerged.

"Practically all the mass night observations of UFOs were unambiguously identified as the effects accompanying the launches of rockets or tests of aerospace equipment," the report concludes. These sightings were mainly associated with activity at the secret rocket base at Plesetsk, north of Moscow.

In about 10-12 percent of the reports, they also identified another category of "flying objects," or as they clarified it, "floating objects." These were meteorological and scientific balloons, which sometimes acted in unexpected ways and were easily misperceived by ground personnel and by pilots.

Specifically, Platov and Migulin describe events on June 3, 1982, near Chita in southern Siberia, and on September 13, 1982, on the far-eastern Chukhotskiy Penninsula. In both cases, balloon launches were recorded but the balloons reached a much greater altitude than usually before bursting. Air defense units reacted in both cases by scrambling interceptors to attack the UFOs.

"The described episodes show that even experienced pilots are not immune against errors in the evaluation of the size of observed objects, the distances to them, and their identification with particular phenomena," the report observes.

The most sensational Russian UFO case of the 1980s involved a story of UFOs nearly triggering nuclear war. This reportedly occurred on October 5, 1982, at a missile base near Khmelitskiy in the Ukraine.

One typical version of this event appeared on an ABC Prime Time Live program which aired on American television in October, 1994. Host Diane Sawyer and correspondent David Ensor presented interviews with former Russian military personnel who described a 900-foot-wide UFO hovering over their missile base while their command consoles switched themselves to "prepare to launch" for 15 seconds before returning to normal. The location was given as Byelokoroviche, but it's the same incident.

Sokolov, who took part in the investigation which began the very next day, presents a very different version in the new report.

The eyewitness reports from more than 50 people, as documented within hours of the sighting, described bright flashing objects on the northern horizon, in the form of "a balloon." Within hours the investigation team had located records of parachute flares and night-bombing exercises occurring at another military base in precisely that direction at precisely that time.

"It should be added," Platov and Sokolov continue, "that the fault of the operation of the command post equipment had nothing to do with the observed phenomena, it just completely accidentally coincided in time." The fault merely involved an indicator light, and there was no evidence the missiles themselves were affected in any way. Nevertheless, the missile base commander, while genuinely alarmed, evidently found it more convenient to blame extraterrestrials rather than his own maintenance troops for the scare.

The official investigators also point out a striking absence of certain types of reports from their files. "In contrast to numerous descriptions of various kinds of contacts with aliens," they write, "there has not been obtained, within the framework of the project which involved the great observational potential of the army and civilian organizations, any message about UFO landings, any message about contacts with pilots of UFOs, any message about the abductions of individuals by UFOs."

"This means," they conclude, "that either the territory of the USSR was, due to any reasons, closed for alien visitations during, at least, 13 years, or that the hypothesis of an extraterrestrial origin of UFOs is inconsistent. Any serious investigator of the problem of UFOs should, at least, face this reality."

Platov and Sokolov clearly are aware that popular press reports, both in Russia and in the West, will undoubtedly still refer to "Soviet UFO secrets." In the harsh economic conditions of post-Soviet Russia, many people, especially military veterans, will continue to be willing to tell any story that other people are willing to pay for.

But their insider positions in one of Earth's greatest government UFO investigations, and their evident lack of any motivation aside from telling the truth as they found it, will make their report a significant contribution to our understanding of what really has been happening regarding this mysterious and fascinating subject.